FAQ

Which endpoint should I use?

Develop and certify on the Simulator (wss:wss-sim.t4login.com/v2); use Live (wss:wss.t4login.com/v2) only after certification.

Do I need to re-subscribe after reconnecting?

Yes. Sessions are not resumable. After any disconnect, log in again and re-subscribe to your markets and accounts, then reconcile order state from the account snapshot.

Why are prices and volumes sent as strings?

To carry exact decimal values with no floating-point rounding, and to support fractional order volumes. Parse them into a native decimal type. See Prices & Data Types.

Do I have to subscribe to an account before trading?

Yes. Orders routed into an account you have not subscribed to are rejected.

MBP or MBO?

Use MBP (Market by Price) for aggregated depth. Use MBO (Market by Order) when you need individual orders or queue position. See Market Data.

Where is the full list of every field?

In the .proto files — see the Message Catalog.

I'm on V1. What changes?

See Migrating from V1.